Technical Note: Correction for the effect of breathing variations in CT pulmonary ventilation imaging

Area of Science:

• Medical Imaging
• Pulmonary Function Testing
• Respiratory Physiology

Background:

• Computed tomography (CT) pulmonary ventilation imaging accuracy is limited by patient breathing variations.
• Conventional CT scanners struggle with motion artifacts during ventilation scans.
• External respiratory signals offer a potential solution for motion correction.

Purpose of the Study:

• To develop and evaluate a method for correcting breathing variations in CT pulmonary ventilation imaging.
• To improve the accuracy and precision of CT-based ventilation assessments.
• To leverage external respiratory signals for motion artifact reduction in CT ventilation imaging.

Main Methods:

• Calculating voxel-wise abdominal surface motion ranges from 4D CT datasets correlated with external respiratory signals.
• Applying a correction factor derived from abdominal motion to CT ventilation values.
• Comparing corrected and uncorrected CT ventilation images against SPECT ventilation images in nine patients.

Main Results:

• The correction method significantly improved CT-SPECT ventilation correlation in 3 out of 9 patients (P < 0.05).
• Trends toward significant improvement were observed in 2 additional patients (P: 0.13-0.18).
• Higher abdominal motion variability correlated with improved correction outcomes.

Conclusions:

• The proposed breathing variation correction method is readily implementable.
• This technique shows potential for enhancing the accuracy of CT pulmonary ventilation imaging.
• Further validation in a larger cohort may confirm broader clinical utility.